Mother-child interaction in families with developmentally handicapped infants may be compromised by alterations in the child's behavior, by the demands these alterations place on the mother's behavior, and by the stresses which accompany parenting a handicapped child. Of special concern is that the interaction may exacerbate rather than buffer developmental delay. Intervention to facilitate functional interaction is therefore important, yet objective assessment to guide intervention is seldom done, in part because of the lack of appropriate tool. The purpose of this study is to investigate whether 1) a set of standardized rating scales (NCAP) differentiate interaction in these dyads from that of normal dyads, 2) interaction scores are related to the HOME assessment of the caretaking environment, 3) specific dysfunctional patterns of behavior can be identified, 4) repeated assessments will detect 5) there are individual differences in interaction measures than in comparison dyads, 6) interaction scores are related to levels of stress, coping resources, and family cohesion and adaptability, and 7) low or declining interaction scores are related to the child's developmental outcome. The same questions will be asked using infant sleep patterns as a measure of parent-child adaptation. Subjects are 30 developmentally handicapped infants and their families, and 30 normal infants and families, matched for SES and age of mother. Mother-child interaction during teaching and feeding and characteristics of the home environment are assessed in the home by direct observation at 8, 12, 18, and 24 months using the NCAP scales. Infant sleep patterns are assessed by 7- day diaries kept by parents. Demographics characteristics and information on infant health and developmental programming are assessed by questionnaire. General life stressors, perceptions of the stressfulness of parenting, and coping resources are also assessed by questionnaire. The child's developmental level is assessed at 8 and 24 months by standardized testing. Family cohesion and adaptability and perceptions of professional services will be assessed by questionnaire at 30 months. Data will be analyzed using appropriate nonparametric and parametric statistics to answer the study's questions. Demonstration that the tools to assess interaction can be used to identify patterns of dysfunctional interaction and an understanding of relationships between patterns of family adaptation and mother-child interaction will be of value to nurses and other professionals providing care to these families.